This invention relates to a foamed glass plate, which is made up of a base layer of foamed glass and a surface layer of dense and transparent or translucent glass and has a decorative pattern at the interface between the two layers, and method of producing same. The foamed glass plate is suitable for use as a decorative surface material in buildings or as a furniture material.
Foamed glass is low in specific gravity and high in heat-insulating ability and gives an attractive appearance, and hence growing interest has been shown in use of foamed glass as a building interior material. However, foamed glass is relatively low in mechanical strength and also in resistance to flawing of surfaces. It is known, as shown in JP-A 60-166239 for instance, to cover at least one major surface of a foamed glass plate with a glass layer which is foamless or low in porosity and tightly bonds to the foamed glass surface. The low-porosity or dense glass layer provides an outer surface fairly resistant to flawing and enhances mechanical strength of the two-layer glass plate as a whole. Besides, the dense glass layer affords the foamed glass plate with glossiness and graveness characteristic of glass and produces an ornamental effect.